1. Field of the Invention
The present invention relates to a socket for electrical parts for detachably holding an electrical part such as semiconductor device, which is called herein as xe2x80x9cIC packagexe2x80x9d, and more particularly, a socket for electrical parts having improvement for restricting deformation of an upper operation member of the socket.
2. Prior Art of the Invention
A known socket for electrical parts of the type mentioned above includes an IC socket for holding an IC package as xe2x80x9celectrical partxe2x80x9d.
Such IC package is so-called a gull-wing type, in which a plurality of IC leads as xe2x80x9cterminalsxe2x80x9d projecting in crank-shape from two opposing side portions of a package body having substantially a rectangular shape.
The IC socket has a socket body which is provided with a mount portion on which the IC package having substantially a rectangular shape is mounted and guide portions located at portions corresponding to four corner portions of the rectangular IC package, the guide portions being adapted to position the IC package at a predetermined position. A partition wall section is also formed to the peripheral portion of the mount portion so as to project upward, the partition wall section being formed with a plurality of slits with a predetermined pitch.
The socket body is provided with a plurality of elastically deformable contact pins which are contacted to or separated from the IC leads of the IC package, respectively. The contact pins have movable contact pieces adapted to contact or separate from the upper surfaces of the IC leads, and the movable contact pieces are inserted, respectively, into the slits formed to the partition wall section.
The socket body is also provided with an upper operation (control) member to be vertically movable in an operative state. The upper operation member of the conventional structure provides a frame-like rectangular shape having opposing two sides to which cap portions are formed. When the upper operation member is lowered against the urging force of the contact pins, operation pieces of the contact pins are pressed outward by the cam portions of the upper operation member, whereby springy (elastic) portions of the contact pins are elastically deformed thereby to separate the movable contact pieces from the IC leads. On the other hand, when the upper operation member is moved upward, the movable contact pieces are returned by the spring (elastic) force of the springy portions of the contact pins and then contact the upper surfaces of the IC leads thereby to press downward the IC leads, thus establishing an electrical connection between the contact pins and the IC leads, respectively.
In the conventional IC socket of the structure mentioned above, however, since a plurality of the contact pins are elastically deformable by the cam portions formed to the upper operation member, replusive force will act on the opposing two side portions of the upper operation member along the entire portions thereof, which results in that the respective side portions will be bent or flexed inward, and more particularly, at the central portions of the side portions, amounts of openings of the contact pins will be reduced by such flexture of these side portions, thus providing a problem. In order to obviate such problem, an attempt to make large the thickness of the upper operation member may be considered, which, however, results in an increased size and an increased weight of the whole apparatus, further involving cost increasing, thus being inconvenient.
An object of the present invention is to substantially eliminate problems or defects encountered in the prior art mentioned above and to provide a socket for electrical parts capable of restricting a deformation of an upper operation member when a replusive force is applied from contact pins.
This and other objects can be achieved according to the present invention by providing a socket for an electrical part comprising:
a socket body having a mount portion on which an electrical part having terminals is mounted;
a plurality of contact pins arranged to the socket body and having an elastic property adapted to contact and separate from the terminals of the electrical part; and
an operation member arranged for the socket body to be vertically movable in a mounted state, the operation member having substantially a rectangular frame shape,
each of the contact pins being formed with a movable contact piece contacting the terminal of the electrical part, the movable contact pin being deformed by the vertical movement of the operation member so as to contact and separate from the terminal,
wherein at least one of the operation member and the socket body is provided with a deformation restriction means, the deformation restriction means being adapted to abut against at least another one of the operation member and the socket body at a time when the operation member takes most lowered position and restrict inward or outward deformation of the operation member due to a replusive force of the contact pin.
In preferred embodiments, the deformation restriction means comprises a rib member formed to an inside portion fo the rectangular operation member and adapted to abut against the socket body at a time of lowering the operation member and to restrict an inward deformation of the operation member from occurring. The deformation restriction rib is formed to substantially a central portion in a longitudinal direction of a long side portion of the rectangular operation member.
A plurality of deformation restriction ribs are formed to substantially central portions in a longitudinal direction of opposing long side portions of the rectangular operation member. Each of said deformation restriction ribs is formed with an inclined surface portion and a perpendicular surface portion which slide along a wall section of the socket body when the operation member is lowered. The movable contact piece is inserted between the deformation restriction ribs.
The deformation restriction rib has an extension which slides along a wall section of the socket body even when the operation member takes an upward moved position.
The deformation restriction rib has a front end formed so as to provide a round shape.
The socket of the structure mentioned above will be preferably applied to an IC socket.
According to the structure and characters of the present invention mentioned above, since the socket is provided with a deformation restriction means, for example, in shape of rib, the deformation of the upper operation member, when lowered, can be effectively restricted or prevented from occurring and, moreover, the opening amount of the contact pins can be ensured without making large the entire structure of the device, i.e. socket.
More specifically, since the deformation restriction ribs may be preferably formed to the central portion of the long side portion, at which the deformation will be most remarkably caused, of the rectangular upper operation member, the deformation of the upper operation member can be more surely restricted, thus being effective and advantageous.
The nature and further characteristic features of the present invention will be made more clear from the following descriptions made with reference to the accompanying drawings.